A new poll suggests President Obama has an excellent chance of winning the youth vote. He leads voters under 30 by a wide margin.

MONTAGNE: But that's not exactly the question in a hard-fought campaign. The president does not lead among young voters by the same margin as in 2008.

INSKEEP: So the real question is whether he can win young voters by enough and turn out enough young voters to gain a decisive advantage.

MONTAGNE: The president is talking directly to students this week in battleground states.

INSKEEP: And today he's at the University of Iowa. NPR's Scott Horsley reports.

SCOTT HORSLEY, BYLINE: President Obama tipped off his college tour at the University of North Carolina, greeting a capacity crowd of 8,000 in the women's basketball arena with what he acknowledged was an easy applause line.

PRESIDENT BARACK OBAMA: I just want to remind you right off the bat, I picked UNC to win it all in March Madness.

(SOUNDBITE OF CHEERING)

HORSLEY: Mr. Obama is not just appealing to college sports loyalties on this trip. He's also appealing to students' pocketbooks. He warned that unless Congress acts soon, interest rates on subsidized student loans are set to double this summer, adding another thousand dollars to the already high cost of college.

OBAMA: The average student who borrows to pay for college now graduates with about $25,000 in student loan debt. That's the average. Some are more. Can I get an amen for that?

(SOUNDBITE OF CROWD RESPONSE)

OBAMA: Yeah - 'cause some folks have more debt than that.

UNIDENTIFIED WOMAN: Amen.

(SOUNDBITE OF LAUGHTER)

HORSLEY: Dominique Nicole Garland, who introduced the president, says she's about to graduate from UNC, thanks to low-cost loans. She worries her younger sister might not have the same opportunity.

DOMINIQUE NICOLE GARLAND: This is not just a case for my sister. This is the case for a lot of students here at UNC, Chapel Hill, and at other colleges and universities all across the country.

HORSLEY: Mr. Obama is making similar appeals this week at the University of Colorado, the University of Iowa, and in the lecture hall of late night television.

(SOUNDBITE OF APPLAUSE, MUSIC "HAIL TO THE CHIEF," FUNKY BASS LINE AND LAUGHTER)

HORSLEY: On Jimmy Fallon's TV show last night, Mr. Obama gamely slow-jammed his pitch for low-cost loans, with backing from Fallon and the house band.

(SOUNDBITE OF TV SHOW, "THE JIMMY FALLON SHOW")

OBAMA: Now is not the time to make school more expensive for our young people.

(SOUNDBITE OF CHEERING)

JIMMY FALLON: Oh, yes.

(SOUNDBITE OF LAUGHTER)

FALLON: You should listen to the president.

(SOUNDBITE OF LAUGHTER)

FALLON: Or as I like to call him, the Preezie of the United Steezie...

(SOUNDBITE OF LAUGHTER AND APPLAUSE)

HORSLEY: Both the president's message and his medium are designed to appeal to young people, who were an important part of Mr. Obama's winning coalition four years ago.

A new poll by Harvard's Institute of Politics shows the president leading his likely Republican rival Mitt Romney by 17 points with voters under 30. That's a wider lead than he held last fall, but it's still only about half the margin he enjoyed with young voters in 2008.

This week, Romney blunted the president's message, saying he also supports keeping interest rates on student loans low. The main debate in Congress seems to be how to pay for that move.

Without a glaring policy difference to highlight, Mr. Obama turned to biography, stressing that he understands student debt on a personal level, not just from reading about it. The president never named Romney but he noted that unlike his wealthy rival, he and First Lady Michelle Obama relied on student loans to get through college and law school.

OBAMA: When we married, we got poor together.

(SOUNDBITE OF CHEERING AND APPLAUSE)

OBAMA: We...

(SOUNDBITE OF APPLAUSE)

OBAMA: We added up our assets and there were no assets.

(SOUNDBITE OF LAUGHTER)

OBAMA: And we added up our liabilities and there were a lot of liabilities, basically in the form of student loans.

HORSLEY: Mr. Obama says he and his wife only finished paying off their loans about eight years ago. And check this out, he said - I'm the president of the United States. A job he's working hard this week to hold onto.